/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jms.connection;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSContext;
import javax.jms.JMSException;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * {@link javax.jms.ConnectionFactory} implementation that delegates all calls
 * to a given target {@link javax.jms.ConnectionFactory}, adapting specific
 * {@code create(Queue/Topic)Connection} calls to the target ConnectionFactory
 * if necessary (e.g. when running JMS 1.0.2 API based code against a generic
 * JMS 1.1 ConnectionFactory, such as ActiveMQ's PooledConnectionFactory).
 *
 * <p>This class allows for being subclassed, with subclasses overriding only
 * those methods (such as {@link #createConnection()}) that should not simply
 * delegate to the target ConnectionFactory.
 *
 * <p>Can also be defined as-is, wrapping a specific target ConnectionFactory,
 * using the "shouldStopConnections" flag to indicate whether Connections
 * obtained from the target factory are supposed to be stopped before closed.
 * The latter may be necessary for some connection pools that simply return
 * released connections to the pool, not stopping them while they sit in the pool.
 *
 * @author Juergen Hoeller
 * @see #createConnection()
 * @see #setShouldStopConnections
 * @see ConnectionFactoryUtils#releaseConnection
 * @since 2.0.2
 */
public class DelegatingConnectionFactory
        implements SmartConnectionFactory, QueueConnectionFactory, TopicConnectionFactory, InitializingBean {

    @Nullable
    private ConnectionFactory targetConnectionFactory;

    private boolean shouldStopConnections = false;

    /**
     * Return the target ConnectionFactory that this ConnectionFactory delegates to.
     */
    @Nullable
    public ConnectionFactory getTargetConnectionFactory() {
        return this.targetConnectionFactory;
    }

    /**
     * Set the target ConnectionFactory that this ConnectionFactory should delegate to.
     */
    public void setTargetConnectionFactory(@Nullable ConnectionFactory targetConnectionFactory) {
        this.targetConnectionFactory = targetConnectionFactory;
    }

    private ConnectionFactory obtainTargetConnectionFactory() {
        ConnectionFactory target = getTargetConnectionFactory();
        Assert.state(target != null, "No 'targetConnectionFactory' set");
        return target;
    }

    /**
     * Indicate whether Connections obtained from the target factory are supposed
     * to be stopped before closed ("true") or simply closed ("false").
     * An extra stop call may be necessary for some connection pools that simply return
     * released connections to the pool, not stopping them while they sit in the pool.
     * <p>Default is "false", simply closing Connections.
     *
     * @see ConnectionFactoryUtils#releaseConnection
     */
    public void setShouldStopConnections(boolean shouldStopConnections) {
        this.shouldStopConnections = shouldStopConnections;
    }

    @Override
    public void afterPropertiesSet() {
        if (getTargetConnectionFactory() == null) {
            throw new IllegalArgumentException("'targetConnectionFactory' is required");
        }
    }


    @Override
    public Connection createConnection() throws JMSException {
        return obtainTargetConnectionFactory().createConnection();
    }

    @Override
    public Connection createConnection(String username, String password) throws JMSException {
        return obtainTargetConnectionFactory().createConnection(username, password);
    }

    @Override
    public QueueConnection createQueueConnection() throws JMSException {
        ConnectionFactory target = obtainTargetConnectionFactory();
        if (target instanceof QueueConnectionFactory) {
            return ((QueueConnectionFactory) target).createQueueConnection();
        } else {
            Connection con = target.createConnection();
            if (!(con instanceof QueueConnection)) {
                throw new javax.jms.IllegalStateException("'targetConnectionFactory' is not a QueueConnectionFactory");
            }
            return (QueueConnection) con;
        }
    }

    @Override
    public QueueConnection createQueueConnection(String username, String password) throws JMSException {
        ConnectionFactory target = obtainTargetConnectionFactory();
        if (target instanceof QueueConnectionFactory) {
            return ((QueueConnectionFactory) target).createQueueConnection(username, password);
        } else {
            Connection con = target.createConnection(username, password);
            if (!(con instanceof QueueConnection)) {
                throw new javax.jms.IllegalStateException("'targetConnectionFactory' is not a QueueConnectionFactory");
            }
            return (QueueConnection) con;
        }
    }

    @Override
    public TopicConnection createTopicConnection() throws JMSException {
        ConnectionFactory target = obtainTargetConnectionFactory();
        if (target instanceof TopicConnectionFactory) {
            return ((TopicConnectionFactory) target).createTopicConnection();
        } else {
            Connection con = target.createConnection();
            if (!(con instanceof TopicConnection)) {
                throw new javax.jms.IllegalStateException("'targetConnectionFactory' is not a TopicConnectionFactory");
            }
            return (TopicConnection) con;
        }
    }

    @Override
    public TopicConnection createTopicConnection(String username, String password) throws JMSException {
        ConnectionFactory target = obtainTargetConnectionFactory();
        if (target instanceof TopicConnectionFactory) {
            return ((TopicConnectionFactory) target).createTopicConnection(username, password);
        } else {
            Connection con = target.createConnection(username, password);
            if (!(con instanceof TopicConnection)) {
                throw new javax.jms.IllegalStateException("'targetConnectionFactory' is not a TopicConnectionFactory");
            }
            return (TopicConnection) con;
        }
    }

    @Override
    public JMSContext createContext() {
        return obtainTargetConnectionFactory().createContext();
    }

    @Override
    public JMSContext createContext(String userName, String password) {
        return obtainTargetConnectionFactory().createContext(userName, password);
    }

    @Override
    public JMSContext createContext(String userName, String password, int sessionMode) {
        return obtainTargetConnectionFactory().createContext(userName, password, sessionMode);
    }

    @Override
    public JMSContext createContext(int sessionMode) {
        return obtainTargetConnectionFactory().createContext(sessionMode);
    }

    @Override
    public boolean shouldStop(Connection con) {
        return this.shouldStopConnections;
    }

}
